The ruling could be expensive for the city, said Howell's attorney, Kristin Rowell. In the past five years alone, hundreds of homeowners in the city have received citations from the city to fix retaining walls in similar circumstances to Howell's, she said. But many may be the city's obligation, and not the property owners', Rowell said.

City attorney Susan Segal said the implications may not be widespread, however. Similar cases in the future will likely be "archaelogical explorations," involving searches of public records going back many decades to when neighborhoods were first developed, without clear evidence of why walls were built or for whose benefit.